A projector is a device that projects an image enlarged through a lens onto a screen by receiving signals of various image apparatuses to display the projected image. Since it is difficult for the projector to separately have a large-volume screen, the image is primarily projected to places such as a wall surface, a ceiling, and the like. When the wall surface, the ceiling, and the like which serve as the screen are not flat planes or have a uniform background color, the image seems to be distorted.